Hello from VT

[rhs856]

Hi, everyone! I have been the (sometimes) proud owner of a 1978 1250 for about 10 years. I came across this site while I was looking for solutions to her current symptoms (runs fine when cold; loses power, blows exhaust out breather; and then dies when hot, tests under 20% leakage with leak-down test).

 

[PACub100]

Welcome to the carnival ride... for your safety, please keep arms / legs in the vehicle and remain seated at all times.

 

[wh cc guy]

Welcome. Someone on here will try to help you.

 

[HKCooper44]

Sounds like an issue I had on a Cadet 104 with a K241, an engine almost identical to yours, save for the bore and stroke. I had a sticking valve that caused the issue.
If I were you, I'd remove the cylinder head and check the bore for any scoring. If you find none, remove the valve chamber cover, and remove both valves. Polish the valve stems on a wire wheel, then ream each valve guide. Lap each valve to its seat then reinstall and set valve clearances. Reinstall the valve chamber cover with a new seal kit.

 

[rhs856]

*duplicate post*

 

[rhs856]

Sounds like an issue I had on a Cadet 104 with a K241, an engine almost identical to yours, save for the bore and stroke. I had a sticking valve that caused the issue.
If I were you, I'd remove the cylinder head and check the bore for any scoring. If you find none, remove the valve chamber cover, and remove both valves. Polish the valve stems on a wire wheel, then ream each valve guide. Lap each valve to its seat then reinstall and set valve clearances. Reinstall the valve chamber cover with a new seal kit.

Thanks, I will give that a look.

 

[Stu]

And everyone here would love to see a pic of what you see when you take the head off.

 

[rhs856]

The cylinder and valves looked pretty good - sorry, I didn't take any pictures. While I was in there, a friend asked about the timing so I checked it against a visual TDC and it was off. I corrected the points and the symptoms went away. As far as I can tell, the problem is solved!

Thanks for the suggestions and I look forward to spending some more time here reading about your cubs.